7.7&#39;-dichloro flavanthrone and the process of making same



Patented Apr. 18, 1933 UNITE srA Es "P T NT OFFICE A IVAN GUBELMANN, OF SOUTH MILWAUKEE, WISCONSIN, ASSIGNOB, BY MESNE AS- SIGNMENTS,-TO E. I. DU FONT DE N EMOURS 8a COMPANY, A. CORPORATION OF DELA- WARE 7.7-DIGHLORO FLAVAN'IHRONE AND THE PROCESS MAKING SAME No Drawing.

a method of preparing 7 .7 -olichloro flavanthrone'a-s it is a valuable vat dyestuff whlch dyes cotton in yellow shades greener than the unsubstituted flavanthrone. It may also be used as starting material for the preparation 10 of other dyestuifs.

Other and further important ob ects of this 7 invention will become apparent from the following description and appended clalms. I have discovered that 7 .7 -dichloro flavanthrone can be prepared from 2-amino-7- chloro anthraquinone, the latter product being the subject of U. S. Patent No. 1,810,012, issued June 16, 1931, Serial No. 203,263 entitled 2-amino-7-chloro anthraquinone and a process of making the same. The 2-amino- 7 -c'hloro anthraquinone can be transformed into the 7 .7-dichloro flavanthrone by the simple adaptation of known methods for the preparation of flavanthrone bodies from beta amino anthraquinone.

Without limiting my process to any particular procedure, the following example serves to illustrate the preferred embodiment 0 of the invention. 1

Example Into 100 parts of nitrobenzene are charged parts of antimony pentachloride. There is washed with about 20 parts of nitrobenzene at 7 0 to 80 C. The residual nitrobenzene is removed by washing with a small amount of alcohol. The product, 7 .7-'dichloro fiavanthrone, is dried and ground.

7.7-dichl0ro flavanthrone is a yellow pow- Application filed September 4, 1928. Serial No. 303,961.

der having most probably-the following formula! r ,7

It is soluble concentratedfsulfuric zacid, imparting thereto yellowish coloration which upon dilution with water separates in yellow flocks. It is practicallylinsoluble in cold benzene, alcohol, nitrobenzene'and sparingly soluble in hot nitrobenzene and anilineq;

It is insoluble in dilute acid or dilute caustic alkalies. It dyes cotton in blue shades from an alkaline hydrosulfite bath which change to greenish yellow shades upon treatment with suitable oxidizing agents. The product dyes cotton much greener shades than the unsubstituted flavanthrone.

I am aware of the fact that numerous de tails of the above method may be varied, as for example other temperatures may be em-; ployed than those given and other condensing agents may be employed, and I, there-' fore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention: 7

1. The process of preparing 7,7-dichloro flavanthrone, which comprises treating 2- amino-7-chloro anthraquinone with antimony pentac-hloride in nitrobenzene at a temperature of about 200 to 210 C.

2. The process of preparing 7,7 -dichloro flavanthrone, which comprises treating 2- amino-7-chloro anthraquinone with antimony pentachloride in nitrobenzene at a temperature of about 200 to 210 C, cooling and filtering to recover 7 ,7-dichloro-flavanthrone.

3. As a new article of manufacture 7,7- dichloro-flavanthrone, having most probably the following formula:

which compound dyes cotton from an alkaline hydrosulfite bath in blue shades which change to greenish yellow upon treatment with suitable oxidizing agents.

4. The process of preparing 7 ,7 -dichloro flavanthron-e, which comprises adding antimony pentachloride and 2-amino-7-chloro anthraquinone to nitro-benzene, slowly heating the mixture until it attains a temperature of from about 200 to 210 C. and maintaining the mixture at this temperature to complete the reaction.

5. The process of preparing 7 ,7-dichloro fiavanthrone, which comprises adding antimony pentachloride and 2-amino-7-ch1oro anthraquinone to nitro-benzene, slowly heating the mixture until it attains a temperature of from about 200 to 210 C. and continuingthe heating at this temperature for a period of approximately two hours.

In testimony whereof I have hereunto subscribed my name.

IVAN GUBELMANN. 

